ObjectiveThis study aimed to examine the effects of binaural beat music (BBM) on sleep quality, heart rate variability, and depression in older people with poor sleep quality in a long‐term care institution.MethodsA single‐blind randomized controlled trial design was employed, and 64 older participants with poor sleep quality were recruited from a long‐term care institution in Taiwan. Participants were randomized into the BBM group or control group and received 14 days of intervention. During the intervention period, participants in the experimental group listened to 20 min of Taiwanese Hokkien oldies embedded with BBM once in the morning and afternoon three times a week. Participants in the control group only listened to Taiwanese Hokkien oldies. Questionnaires and heart rate variability analysis were used to assess participants' sleep quality, heart rate variability, and depressive symptoms.ResultsSignificant improvements were observed in sleep quality, along with an increase in heart rate variability means of heart rate and normal sinus beats, and a decrease in low‐frequency normalized units and depression severity in the BBM group after the intervention. In the control group, effects on sleep quality were inconsistent, heart rate variability showed significant improvements in some autonomic nervous function regulation, and depression severity was significantly decreased. Furthermore, the BBM group showed a significant improvement in sleep quality and a significant reduction in sympathetic nervous activity compared with the control group.ConclusionThis study demonstrates that 14 days of BBM intervention, a non‐invasive intervention, could improve sleep quality and depression in older people with poor sleep quality in long‐term care institutions. Geriatr Gerontol Int 2024; ••: ••–••.